利用实时荧光定量PCR法检测转基因水稻外源基因拷贝数的研究

转基因植物中外源基因拷贝数是影响目的基因表达水平和遗传稳定性的重要因素，因此外源基因拷贝数的检测成为转基因研究的关键．利用高通量、快速、灵敏的SYBR Green Ⅰ荧光定量实时PCR法，检测了转大麦烟酰胺合成酶基因（NASl）水稻中外源基因拷贝数．以蔗糖磷酸合成酶基因（SPS）作为水稻的内源参照基因．通过梯度稀释法．分别获得了NAS1和SPS基因的Ct值与起始模板数的相关性标准曲线，相关系数分别为0．99976和0．99571，相关性高．通过目的基因NAS1和水稻内源参照基因SPS起始模板数的比较，获得了目的基因在转基因水稻中的拷贝数。在8株转基因株系中，1株为假阳性，1株拷贝数为1，3株拷贝数为2，其余3株拷贝数分别为3、4和7．而阴性对照拷贝数为0．这种方法快速、简便、准确，可以满足转基因育种工作中对后代优良株系的选择．     

一种检测慢病毒滴度的实时荧光定量PCR方法

目的:建立一种有效、灵敏、准确的慢病毒滴度的分子检测方法。方法:分别构建慢病毒调控元件WPRE和单拷贝基因白蛋白(Alb)基因的重组质粒,紫外吸收法测量后经数学换算得到相应的拷贝数,以梯度稀释质粒为模板,利用基于SYBR Green的荧光定量PCR制作标准曲线,最后将待测样品的Ct值代入标准曲线,根据相应公式计算慢病毒滴度。结果:WPRE元件和Alb基因质粒的标准曲线回归方程分别为y=-4.255x+46.047、y=-2.8735x+35.831,相关系数R2均大于0.99,扩增效率E均大于95%,且熔解曲线波峰单一。计算获得不同稀释比例待测病毒的滴度为(4.3±0.9)×106TU/mL。结论:基于SYBR Green的实时荧光定量PCR方法操作简便,能够准确测定慢病毒滴度。     

利用荧光定量PCR分析c-Ha-ras基因在C57-ras转基因小鼠中的拷贝数

目的:利用real-time PCR建立检测C57-ras转基因小鼠中外源c-Ha-ras基因拷贝数的简便方法,为药物安全性评价C57-ras转基因小鼠模型的繁殖和筛选提供数据支持。方法:以自建的人原癌基因c-Ha-ras转基因小鼠为研究对象,利用SYBR GreenⅠ荧光定量PCR的绝对定量法测定3个C57-ras转基因小鼠系的c-Ha-ras基因Ct值,通过与内参基因GAPDH比较计算获得转基因的拷贝数。结果:内参基因GAPDH的标准曲线为lg NGAPDH=-2.852Ct+26.236,外源基因c-Ha-ras的标准曲线为lg NRAS=-3.068Ct+39.186;经计算,NO.2、NO.3、NO.5系的F6代拷贝数分别为4、4和3,并且系内不同个体间拷贝数一致。结论:利用SYBR GreenⅠreal-time PCR技术建立了检测C57-ras转基因小鼠中外源基因拷贝数的方法,该方法操作简单,节约成本,为C57-ras致癌性模型的选留和应用提供了基础和技术手段,也为其他类似转基因品系中转基因拷贝数的确定提供了一种参考方法。     

抗除草剂转基因大豆插入拷贝数及其旁侧序列分析

目的:确定抗除草剂转基因大豆外源基因拷贝数和其插入位点侧翼序列.方法:采用绝对定量PCR法测定转EPSPS基因大豆中外源基因拷贝数,内参照基因标准曲线选用大豆凝集素(Lectin)基因为标准品,外源基因标准曲线以含EPSPS基因的阳性质粒为标准品.采用基因组步移技术和巢式PCR方法确定抗除草剂转基因大豆插入位点旁侧序列.结果:抗除草剂转基因大豆外源基因的拷贝数为1.CaMV35S上游扩增887bp,NOS下游扩增1 340bp.结论:明确了EPSPS外源基因在转基因大豆中为单拷贝,转基因大豆插入位点附近大豆基因组发生了DNA重排.     

人4型腺病毒拷贝数SYBR Green Ⅰ实时定量PCR检测方法的建立

目的:建立检测人4型腺病毒拷贝数的荧光定量PCR方法。方法:提取本实验室构建的4型腺病毒全基因组质粒,以梯度稀释质粒为标准模板,选取人4型腺病毒六邻体区域基因设计一对特异性引物,进行SYBR GreenⅠ荧光定量PCR扩增并制作标准曲线。结果:标准曲线为y=-4.284x+53.468,由全基因组质粒所构建的标准曲线线性关系良好,扩增反应Ct值与拷贝数的对数呈线性关系(R2=0.999 609),检出敏感度可达1×102拷贝/μL,且与其他几种腺病毒无交叉反应。用该方法检测4型腺病毒感染细胞2、12和24 h后的病毒拷贝数,其病毒拷贝数随时间增加,与细胞病变(CPE)变化保持一致,且荧光定量PCR的测量结果稳定(变异系数6%)。结论:建立了检测人4型腺病毒基因拷贝数的荧光定量RT-PCR方法,该方法灵敏度高、特异性强。     

版纳微型猪近交系TNF-α基因mRNA实时荧光定量PCR检测方法的建立

目的快速、灵敏、可靠的检测与临床多种疾病密切相关的重要基因TNF-α的表达情况,构建TNF-α基因及内参GAPDH基因荧光定量PCR质粒标准品。方法利用版纳微型猪近交系4～6月龄猪建立动物模型,提取皮肤创面总RNA,设计特异引物,进行RT-PCR扩增。纯化目的片段与pMD18-T载体连接,转化宿主菌DH5α,提取重组质粒DNA,并经酶切、PCR和测序鉴定,计算重组质粒原液拷贝数浓度并制备梯度浓度标准品,进行实时荧光定量PCR,生成标准曲线。结果建立的TNF-α基因和GAPDH内参基因mRNA表达实时荧光定量PCR检测方法灵敏度分别可达103和105拷贝,线性范围分别为103～109和105～109拷贝,阈值循环数(Ct)与PCR体系中起始模板量的对数值之间存在的线性关系R2分别为0.993和0.999,扩增效率E分别为111.073%和95.948%。结论成功的构建了版纳微型猪近交系TNF-α基因质粒标准品和标准曲线,并用内参基因GAPDH进行校正,此方法可为探讨TNF-α基因在临床多种疾病中所发挥的分子机理奠定基础。     

茶树α-tubulin基因实时荧光定量RT-PCR方法的建立

目的:建立茶树α-tubulin基因实时荧光定量RT-PCR方法。方法:根据GenBank中茶树α-tubulin基因保守区域设计一对特异性引物,将PCR扩增得到的α-tubulin基因克隆到pTG19-T载体上,构建的重组质粒标准品经1/10梯度稀释后,用SYBR GreenⅠ染料法绘制标准曲线,并进行融解曲线分析。结果:标准曲线Ct值检测范围为14.56~27.09,相关系数为0.991,溶解曲线分析显示产物为特异的单峰,其Tm值为81±0.3℃。结论:建立了茶树α-tu bulin基因实时荧光定量RT-PCR法,为以α-tubulin作为茶树内参基因进行功能基因表达差异研究奠定了基础。     

SYBR Green Ⅰ实时荧光定量RT-PCR测定猴免疫缺陷病毒RNA拷贝数方法的建立

目的 建立SYBR Green Ⅰ荧光染料实时定量RT-PCR方法,测定猴免疫缺陷病毒(SIV)RNA拷贝数.方法 巢式RT-PCR扩增SIV病毒RNA gag基因上1360-1837之间的长度为477 bp的片段,将该片段克隆到pGEM T载体上,构建pGEM-SIVgag477质粒.该质粒经限制性内切酶Not I酶切后,进行体外转录,转录出的RNA产物(RS)纯化后10倍系列稀释,作出标准曲线,作为SIV病毒RNA荧光定量检测的外标准品.结果 应用Qiagen公司QuantiTect SYBR GREEN RT-PCR Kit,该标准品可精确定量到100 copies/μL.结论 制备的RS外标准品纯度高,SYBR Green Ⅰ荧光染料实时定量RT-PCR法特异性、敏感性高,稳定性好,可用于定量测定猴免疫缺陷病毒(SIV)RNA拷贝数.     

SYBR Green I实时荧光定量RT-PCR测定猴免疫缺陷病毒RNA拷贝数方法的建立

目的建立SYBR Green I荧光染料实时定量RT-PCR方法,测定猴免疫缺陷病毒(SIV)RNA拷贝数。方法巢式RT-PCR扩增SIV病毒RNAgag基因上1360-1837之间的长度为477 bp的片段,将该片段克隆到pGEMT载体上,构建pGEM-SIVgag477质粒。该质粒经限制性内切酶NotⅠ酶切后,进行体外转录,转录出的RNA产物(RS)纯化后10倍系列稀释,作出标准曲线,作为SIV病毒RNA荧光定量检测的外标准品。结果应用Qiagen公司QuantiTect SYBR GREEN RT-PCR Kit,该标准品可精确定量到100 copies/μL。结论制备的RS外标准品纯度高,SYBR Green I荧光染料实时定量RT-PCR法特异性、敏感性高,稳定性好,可用于定量测定猴免疫缺陷病毒(SIV)RNA拷贝数。     

拟除虫菊酯降解酶基因APs实时荧光定量PCR检测方法的建立

本研究建立了一种能够快速、灵敏地检测来源于铜绿假单胞菌GF31中拟除虫菊酯降解酶基因APs的SYBR GreenⅠ相对实时荧光定量PCR方法。通过克隆构建APs目的基因及16S rRNA内参基因重组质粒,分别制备了质粒标准品SgI-pET30a、PA-pET30a、Pep-pET30a以及16S r RNA-p ET30a;绘制标准曲线,建立了实时荧光定量PCR体系。结果显示,在质粒标准品浓度为0.001~10 ng范围内,实时定量PCR标准曲线的线性关系良好,APs和16S r RNA的标准曲线R~20.99,扩增效率=95%~105%;熔解曲线呈单峰,特异性良好;扩增曲线呈S型,CT值在各梯度间均匀变化、重复性好;将建立的相对实时荧光定量PCR方法应用于检测工程菌及野生菌APs基因的m RNA表达水平,2~(-△△Ct)法计算得工程菌SgI、PA及Pep的表达量分别为野生菌的1 898、1 314和956倍。     

农杆菌介导的半夏凝集素基因(Pinellia Ternate Agglutinin Gene,pta)对小麦的遗传转化及鉴定

以甘肃主要推广春小麦品种陇春22幼胚为转基因受体材料,建立了农杆菌介导的小麦遗传转化体系。以预培养4天的幼胚愈伤组织为受体,C58c1农杆菌菌株为供体,将含有半夏凝集素基因的重组质粒pBIpta转入了小麦,经G418 25 mg/L抗性筛选、PCR检测和荧光定量PCR检测共获得转基因植株3株,外源基因的插入拷贝数分别为2、1、3。同时对转基因小麦的T₁代植株进行了PCR检测和抗虫性分析,表明半夏凝集素基因在转基因植株的后代中得到了遗传并有一定的抗蚜虫作用。     

Anthocyanin expression in marker free transgenic wheat and triticale embryos

Wheat and triticale plants were transformed by bombardment of isolated scutella with a genetic construct consisting of the two anthocyanin biosynthesis regulatory genes, C1 and Bperu, each under the control of the Ltp1 embryo-specific promoter. Transgenic plants were obtained in the absence of selective pressure and selectable marker gene at a transformation frequency of 0.93% and 1.55% in triticale and wheat, respectively. Initial screening of T₀ lines was performed by polymerase chain reaction (PCR), and further confirmation of PCR positives was done using real-time PCR and by phenotypic observation. In this study, quantitative real-time PCR (qRT-PCR) was developed to determine the transgene copy number in transgenic wheat and triticale. A conserved wheat housekeeping gene, puroindoline-b, was used as an internal control to calculate the transgene copy number in wheat and the SYBR green detection method with a standard curve, constructed on the basis of serially diluted plasmid, was used to calculate the transgene copy in triticale. Estimated transgene copies varied from 3 to 8 in wheat and 4 to 7 in triticale lines. The presence of anthocyanin regulatory genes, promoter, and termination sequences was detected in six wheat lines and four triticale lines. However, anthocyanin-pigmented embryos were only observed visually in mature T₁ seeds of two transgenic wheat lines and a single triticale line. Multisite insertion and reorganization of transgenes was likely the explanation for the failure of expression for the anthocyanin genes in the remaining wheat and triticale transgenic lines.     

SYBR Green I and TaqMan quantitative real-time polymerase chain reaction methods for the determination of amplification of Plasmodium falciparum multidrug resistance-1 gene (pfmdr1)

The pfmdr1 gene, which encodes P-glycoprotein homolog 1, has been shown to be a reliable marker of resistance for Plasmodium falciparum related to artesunate and mefloquine combination therapy. The aims of this study are to investigate the copy number of pfmdr1 in P. falciparum isolates collected from the 4 malaria-endemic areas of Thailand (Kanchanaburi, Mae Hongson, Ranong, and Tak) along the Thailand-Myanmar (Burma) border (Thai-Myanmar border) by using SYBR Green I and the standard method TaqMan real-time polymerase chain reaction (RT-PCR) and to compare the efficiency (sensitivity and specificity) of SYBR Green I with TaqMan RT-quantitative (q)PCR methods in determining pfmdr1 gene copy number. Ninety-six blood samples were collected onto filter paper from patients with uncomplicated falciparum malaria who attended malaria clinics in the Kanchanaburi (n = 45), Mae Hongson (n = 18), Ranong (n = 11), and Tak (n = 22) provinces in Thailand. Parasite genomic DNA was extracted from dried blood spots by using QIAcube? automated sample preparation. Pfmdr1 gene copy number was determined by TaqMan (63 samples) and SYBR Green I (96 samples) real-time PCR. Seventy-one (74.0%), 14 (14.6%), 10 (10.4%), and 1 (1%) isolates carried 1, 2, 3, and 4 pfmdr1 gene copies, respectively. Forty-three of 48 (89.6%), 6 of 11 (54.5%), and 3 of 4 (75.0%) samples, respectively, showed agreement with results of 1, 2, and 3 pfmdr1 gene copies as determined by both methods. The efficiency of SYBR Green I in identifying pfmdr1 gene copy number was found to be significantly correlated with that of TaqMan. Considering its simplicity and relatively low cost, SYBR Green I RT-qPCR is therefore a promising alternative technique for the determination of pfmdr1 copy number.     

粪便中肠球菌SYBR GreenI荧光定量PCR检测方法的建立

目的利用SYBR GreenI荧光定量PCR方法,建立肠球菌实时荧光PCR检测方法,并初步应用于粪便中肠球菌的检测。方法根据GenBank发表的肠球菌23S rRNA基因序列的保守区域设计合成特异性的引物;利用构建的质粒标准品绘制两种标准曲线,构建基因拷贝数、细菌数为分析指标的定量分析模型并初步应用于粪便标本的检测分析。结果所建立的SYBR GreenI荧光定量PCR方法检测灵敏度可达7个拷贝数/reaction。粪便样本根据实时荧光定量PCR方法所得的理论数值与培养菌值之间差异无显著性(P>0.05)。非炎性腹泻标本中菌数与健康成人标本中菌数差异无显著性(P>0.05)。灵敏度曲线所得的数值大于菌数标准曲线,可能由于DNA提取过程中存在部分的损失。检测粪便标本结果显示SYBR GreenI荧光定量PCR方法较平板计数法敏感、快捷、简便。结论本研究建立了一种灵敏、特异、简便易行的肠球菌定量检测方法。     

SYBR GreenⅠ实时荧光定量RT-PCR测定肠道病毒71型（EV71）RNA拷贝数方法的建立

目的建立SYBR GreenⅠ荧光染料实时定量RT-PCR方法,测定实验动物等来源的EV71病毒RNA。方法运用EV71VP1保守区引物,优化real time RT-PCR条件,运用NASBA方法扩增EV71病毒RNA,计算拷贝数,经10倍系列稀释做出标准曲线,作为EV71病毒RNA定量检测的外标准品。结果应用Qiagen公司QuantiTect SYBR Green RT-PCR Kit,该标准品可精确定量到100copies/μL,PCR扩增效率达到99.5%。结论 SYBRGreenⅠ荧光染料实时定量PCR法测定EV71病毒RNA拷贝数的方法敏感性高、稳定性好,可用于EV71病毒RNA载量的定量测定。     

Using real-time PCR to determine transgene copy number in wheat

Transgene copy number is usually determined by means of Southern blot analysis which can be time consuming and laborious. In this study, quantitative real-time PCR was developed to determine transgene copy number in transgenic wheat. A conserved wheat housekeeping gene,puroindoline-b, was used as an internal control to calculate transgene copy number. Estimated copy number in transgenic lines using real-time quantitative PCR was correlated with actual copy number based on Southern blot analysis. Real-time PCR can analyze hundreds of samples in a day, making it an efficient method for estimating copy number in transgenic wheat.     

小麦脱水素基因wzy2表达量实时荧光定量PCR方法的建立和应用

以陕合6号小麦品种为材料,用SYBR GreenⅡ染料,参照小麦脱水素wzy2和-βactin基因序列设计引物,建立小麦wzy2基因的实时荧光定量PCR分析方法.结果表明:通过对标准品标准曲线和熔解曲线分析,其标准曲线的Ct值检测范围为12~30,PCR扩增效率高达111.3%;不同的标准品扩增曲线的间距为3.078,接近于理想值3.32,且可显示产物特异的单峰,引物的特异性扩增强.小麦脱水素基因wzy2表达量实时荧光定量PCR的测定结果表明,小麦脱水素基因wzy2在胁迫24 h的表达量明显高于胁迫12 h的表达量.     

Quantitative real-time PCR as a screening tool for estimating transgene copy number in WHISKERS™-derived transgenic maize

. Quantitative real-time PCR (qRT-PCR) was adapted to estimate transgene copy number in transgenic maize callus and plants. WHISKERS™-derived transgenic callus lines and plants were generated using two different gene constructs. These transgenic materials represented a range of copy number. A 'standard curve' was established by mixing plasmid DNA with non-transgenic genomic maize DNA using a calculated ratio of target gene to host genome size. 'Estimated' copy number in the callus lines and plants using qRT-PCR was correlated with the 'actual' copy number based on Southern blot analysis. The results indicated that there was a significant correlation between the two methods with both gene constructs. Thus, qRT-PCR represents an efficient means of estimating copy number in transgenic maize.